Create EXPECT_QUIC_BUG macro, and modify QUIC tests to use it.

net/tools/quic/quic_simple_server_stream_test.cc

Index: net/tools/quic/quic_simple_server_stream_test.cc
diff --git a/net/tools/quic/quic_simple_server_stream_test.cc b/net/tools/quic/quic_simple_server_stream_test.cc
index 2a0de32acfa60e0a0fd4b24916ef8580d22cdc07..0c6039d229309c3d2bc848113929d1ac94a56fe2 100644
--- a/net/tools/quic/quic_simple_server_stream_test.cc
+++ b/net/tools/quic/quic_simple_server_stream_test.cc
@@ -190,7 +190,6 @@ class QuicSimpleServerStreamTest
                  crypto_config_.get(),
                  &compressed_certs_cache_),
         body_("hello world") {
-    FLAGS_quic_always_log_bugs_for_tests = true;
     SpdyHeaderBlock request_headers;
     request_headers[":host"] = "";
     request_headers[":authority"] = "www.google.com";
@@ -468,9 +467,9 @@ TEST_P(QuicSimpleServerStreamTest, SendReponseWithPushResources) {
 TEST_P(QuicSimpleServerStreamTest, PushResponseOnClientInitiatedStream) {
   // Calling PushResponse() on a client initialted stream is never supposed to
   // happen.
-  EXPECT_DFATAL(stream_->PushResponse(SpdyHeaderBlock()),
-                "Client initiated stream"
-                " shouldn't be used as promised stream.");
+  EXPECT_QUIC_BUG(stream_->PushResponse(SpdyHeaderBlock()),
+                  "Client initiated stream"
+                  " shouldn't be used as promised stream.");
 }
 
 TEST_P(QuicSimpleServerStreamTest, PushResponseOnServerInitiatedStream) {